Make valkey compatible with redis-sentinel to start sentinel (valkey-…

…io#731)

We already have similar changes to check-rdb / check-aof, apply
this change to sentinel.

Fixes valkey-io#719.

Signed-off-by: Binbin <binloveplay1314@qq.com>
Signed-off-by: Ping Xie <pingxie@google.com>

src/server.c

@@ -6765,6 +6765,9 @@ void memtest(size_t megabytes, int passes);
 int checkForSentinelMode(int argc, char **argv, char *exec_name) {
     if (strstr(exec_name,"valkey-sentinel") != NULL) return 1;
 
+    /* valkey may install symlinks like redis-sentinel -> valkey-sentinel. */
+    if (strstr(exec_name, "redis-sentinel") != NULL) return 1;
+
     for (int j = 1; j < argc; j++)
         if (!strcmp(argv[j],"--sentinel")) return 1;
     return 0;